Ore-flotation apparatus.



H18. 81 E. A. COLBURN ORE FLOTATION APPARATUS.

APPUCATION r1110 OCT. 31. 19l6.-

1;Q26,063. I Patented May 15,1917.

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ORE-FLOTA'TION APPARATUS.

Patented May 15, 1917.

Driginal application filed may 31, 1916, Serial Nb. 1043,9 t7.llividedand this application filed October 31, 1916. Serial No. 128,721.

separating valuable particles in finely divided ore, by what is commonlyknown as the flotation process.

This application is divisional ofour application Serial Number 100,947,on ore flotation process, filed May 31, 1916, and allowed- October 171916, it being the object of the present invention to provide anassociation of simple mechanical devices by which our separation processmay be effectually car ried out.

The process above referred to consists in mixing ore pulp with an oilorother substance having a selective afinity for the desired valuableparticles, agitating and emulsifying this mixture with the addition of alimited quantity of air or other gas, under a pressure less thanatmospheric, and then conducting the emulsified mixture to a separatereceptacle in which the froth can rise under atmospheric pressure.

In order to carry out this process we have designed. an apparatus theprincipal elements of which are a settling tank the con tents of whichare under atmospheric pressure and a mixing chamber provided with anoutlet which connects with a settling tank and with an inlet forore-pulp which con nects with a conveniently ore and water.

The mixing chamber contains a movable disposedsupply of element adaptedto thoroughly agitate andemulsify its contents, and suitable means are,provided to maintain during the agitative action, a partial vacuum inthe chamber which greatly expedites and promotes the process ofseparation.

By subjecting the finely divided ore during the emulsification step ofthe process, to a partial vacuum, the envelops of gas and colloidalmatter which surround the s'nlfid chamber with an outlet-opening whichexparticles contained in the ore are expanded and disrupted and the oilhaving a natural aiiinity' for the sulfids, immediately attaches itselfthereto after the particles have been bared.

The partial vacuum constantly maintained in the mixing chamber,furthermore atomizes the air through the pulp and produces other resultsof minor advantage, all of which cooperate in obtaining a product whichuponentering the settling chamber will by natural flotation be cleanlydivided, it being understood that the oil-coated sulfid particles, as adirect result of the mixing action under less than atmospheric pressure,will rise naturally and easily to the surface while the gangue settlesto the bottom of the tank. The air atomized through the pulp 70 alsorises to the surface of the material in the settling chamber and a frothis formed in which the values are entrapped and which may be removedfrom the tank either by natural overflow or by the use of a suitableskimming device.

The partial vacuum required in the mix ing chamber during theemulsification process is preferably obtained by providing the ceeds thefeed opening in area, a proportion of four to one having been found toproduce satisfactory results.

The partial vacuum may also be obtained.

by connecting the mixing chamber with a 5 I suction pump through theintermediary of a vacuum chamber, or by any other expedient WhICh may befound best adapted for the purpose.

The oil and air are admitted to the material under treatment, preferablythrough "openings in the conduit which" connects- With the inletopeningof the "mixing chamber, the flow through said openings bemg controlledbyvalves which are connected for synchronous movement to automaticallyproportionate the quantities of oil and air admltted during a givenperiod in the operation of theapparatus.

- Having thus briefly described the purposes, operation and results ofour improved apparatus, we will now proceed to explain the constructionof the same in detail with reference to the accompanying drawings in thevarious views of which-like parts are similarly designated, and in whichFigure 1- represents a sectional elevation of the elements comprised inthe apparatus, in their cooperative relation,

Fig. 2, a vertical section throughthe mixing chamber of the apparatustaken along the line 2- -2, Fig. 1, drawn to an enlarged scale,

- The tank has at its-upper edge an overflow 3 for the froth, producedin the flotation process, and in its bottom an outlet 4 for the settlinggangue.

The mixing chamber-5 of the apparatus consists in its preferred form ofan upright circular casing 6 in which a mixing element has a rotarymovement about a'horizontal axis. The casing has a feed opening 7 whichby means of a conduit 8 is connected with an elevated source of oresupply 9, and an outlet 10 of comparatively large diameter, whichconnects with a conduit 12 extending into the settling or frothingtank.2.

The mixing element may be of any suitable construction, preference beinggiven to a device of the character shown in Figs. 2 and 3 of thedrawings.

I The feed opening 70f the mixing chamber is in this construction formedcentrally in one of the sides of the casing 6, and the outlet opening 10is disposed tangentially at the upper end of the same. The feed-openingis connected with the before mentioned conduit 8 by a nozzle 13 thecross-sectional area of WlllCll is less than one-fourth the area of theoutlet 10.

The nozzle has an opening for the admission of air theflow through whichis controlled by a valve 14 which is yieldingly held upon its seatagainst atmospheric pressure by a spring 15.

The oil used in the flotation process, enters the nozzle through anopening theadmission of ,oil to which is controlled by a needlevalve 16which opens and closes the outlet of a pipe 17 communicating'with thesource of oil supply.

The two valves are connected-to move in unison by a lever 18, wherebythe quantities of air and oil admittedat onetime to the material.passing through the nozzle, are automatically proportioned.

The spring 15 is. made of sufficient strength to maintain the partialvacuum in the mixing chamber constantly at a predetermined pressure.

The casing 6 has centrally disposed stuffing boxes 19 for the support ofa shaft 20 which imparts a rotary movement to the mixing element withinthe chamber 5.

. This element consists of a disk-shaped member 21 mounted on the shaft20 and provided with a series of radial, outwardly projecting vanes 22which in their outer longitudinal edges have recesses to admitcorrespondingly formed tongues 23 on a stationary member 24 which isfixed at the opposite side of the chamber.

During rotation of the shaft these tongues pass through the recesses ofthe rapidly rotating member 21 and thereby effect a thorough agitationand emulsification of the ore pulp, oil and, air.

In the construction shown in Fig. 4, a

mixing chamber 25 is connected by a conduit 26 with a reservoir 27 inwhich a vacuum of determinate pressure is maintained by a suction pump28. The mixing element mounted within the chamber 25 consists of aseries of paddles which radiate from a rotary vertical shaft 29.

In the operation of our apparatus, the orepulp, oil and air areintroduced into the mixing chamber in predetermined proportions ashereinbefore explained, the partial .Vacuum maintained in the mixingchamber bares the sulfids of the ore, which are immediately coated withoil, and the entire mass contained in the chamber is thoroughly agitatedand emulsified and intermixed with the air or other gas which isatomized by the vacuum. The mixture is discharged from the mixingchamber into the settling tank in which it is brought to a comparativecondition of rest and in which the coated sulfid particles and atomizedair rise to the surface where theycongregate into a froth in which thevalues of the ore are entrapped. The froth passes across the overflowinto a launder 30 and its movement may be expedited by the use of askimmer such as that shown at 31 in Fig. 1.

The -gangue settling to the bottom of the settling tank is discharged atintervals through the normally valve-closed outlet 4.

While in most cases a singletreatment of the ore by our process issufiicient to extract practically all the values it contains, the

treatment of unusually refractory ores may be repeated by the use of asecond apparatus similar to that described, the mixing cham-' ber ofwhich connects with the gangue outlet of the settling tank of the firstapparatus.

The two settling tanks may under these conditions' be connected by .aconduit 32 for maintaining their liquid contents on an even.

level. I

Having thus described our invention what matinee we claim and desire toPatent is: i

1. Apparatus for separating valuable particles of finely divided ores bya flotation process, comprising in'combination, a mixing chamber havinga feed-opening and an outlet, a mixing element operating in said mixingchamber for the agitation and emulsification of its contents, means formaintaining a partial vacuum in the mixing chamber during the operationof said element, and a settling chamber under a higher pressure,connected with said outlet.

2. Apparatus for separating valuable particles of finely divided ores bya flotation process, comprising in combination, a mixing chamber havinga feed-opening, an inlet for introducing a gas into material admittedthrou hsaid feed-opening, and an outlet, a mixing element operating insaid mixing chamber for the agitation and emulsification of itscontents, means for maintaining a partial vacuum in the mixing chamberduring the operation of said element, and a settling chamber under ahigher pressure, connected with said outlet.

8. Apparatus for separating valuable particles of finely divided ores bya flotation process, comprising in combination, a mixsecure byLettersing chamber having a feed-opening, aninlet.

for introducing a substance having a selective affinity for the desiredvaluable particles, into material admitted through said feed-opening,and an outlet, a mixing element operating in said mixing chamber for theagitation and emulsification of its con tents, means for maintaining apartial vacuum in the mixing chamber during the operation of saidelement, and a settling charm her under a higher pressure, connectedwith said outlet.

4. Apparatus for separating valuable particles of finely divided ores bya flotation process, comprising in combination, a mixing chamber havinga feed-opening, an inlet for introducing an oil into material admittedthrough said feed-opening, and an outlet, a mixing element operating insaidmixing chamber for the agitation and emul sification of itscontents, means for main taining a partial vacuum in the mixing chamberduring the operation of said element, and a settling chamber under ahigher pressure, connected with said outlet.

53. Apparatus for separating valuable particles of finely divided oresby a flotation process, comprising in combination, a mixing chamberhaving a feed-opening, inlets for introducing a gas and an oil into material. admitted through said feed-openin and outlet, a mixing elementoperating in said mixin chamber for the agitation and emulsiiication ofits contents, means for maintaining a partial vacuum in the mixingchamber during the operation or said element, and a settling chamberunder a higher pressure, connected with said outlet.

6. Apparatus for separating valuable particles of finely divided ores bya flotation process, comprising in combination, a mixing chamber havinga feed-opening, an inlet .ing chamber having-a feed-opening, inlets forintroducing a gas and an oil into material admitted through saidfeed-opening, and an outlet, a mixing element operating in said mixingchamber for the agitation and emulsification of its contents, means formaintaining a partial vacuum in the mixing chamber during the operationof said element, a valve automatically regulating the introduction of agas through the gasinlet, a valve cooperating with the other valve toregulate the introduction of oil through the oil-inlet, and a settlingchamber under a higher pressure, connected with said outlet.

8. Apparatus for separating valuableparticles'of finely divided ores bya flotation process,v comprising in combination, a mixing chamber havinga teed-opening and an outlet, a mixing-element operating in said mixingchamber for the agitation and emulsification of its contents, saidfeed-opening being relative to said outlet, of reduced area formaintaining a partial vacuum in the mixin chamber during the operationof said e ement, and a settling chamber under a higher pressure,connected with said out let.

9. Apparatus forseparating valuable particles of finely divided ores bya flotation process, comprising in combination, a mixing chamber havinga feed-opening and an outlet, a mixing element operating in said mixingchamber for the agitation and emulsification of its contents, saidfeed-opening having an area not exceeding one-fourth the area of saidoutlet for maintaining a partial vacuum in the mixing chamber during theoperationof said element, and a settling chamber under a higherpressure, connected with said outlet. 1

10. Apparatus for separating valuable particles of finely divided oresby a flotation process, comprising in combination, a mixing chamberhaving a feed-opening and an outlet, a mixing element operating in saidmixing chamber and comprising a rotary member and a fixed member havingmter meshing parts for the agitation and emulsification of the contentsof said chamber, means for maintaining a partial vacuum in the mixingchamber during the operation of said element, and a settling chamberunder a higher pressure, connectedwith said outlet.

11. Apparatus for separating valuable particles of finely divided oresby a flotation process, comprising in combination, a mix ing chamberhaving a feed-opening and an outlet, a mixing element operating in saidmixing chamber and comprising a rotary member and a fixed member havingcooperative vanes for the agitation and emulsifica- 12. Apparatus forseparating valuable particles of finely divided ores by a flotationprocess, comprising in combination, a mix ing chamber having afeed-opening andan outlet, a mixing element operating in said mixingchamber for the agitation and emulsification of its contents, means formaintaining a partial vacuum in the mixing chamber during the operationof said element, a settling chamber under a higher pressure, connectedwith said outlet, and means for feeding material into the mixing chamberby gravitation and discharging the mixture produced in the latter, intothe settling chamber.

In testimony whereof we have affixed our signatures in presence of twowitnesses.

; HERBERT O. COLBURN.

ERNEST A. COLBURN. Witnesses:

G. J. 'RoLLANm-rr,

L. Rumors.

